Which vaccines are live vaccines?

Which vaccines are live vaccines?

• A. MMR and Varicella vaccines
• B. MMR and HPV vaccines
• C. Varicella and Influenza vaccines
• D. IPV and Meningococcal vaccines

Answer: (A)

Live vaccines use weakened forms of viruses or bacteria that can still replicate in the body, triggering a strong and lasting immune response without causing disease in healthy people. The two vaccines that fit this pattern are measles-mumps-rubella (MMR) and varicella (chickenpox). They contain attenuated (weakened) viruses that replicate just enough to train the immune system. Other options don’t fit the live-vaccine category. HPV vaccines are recombinant subunit vaccines—they use viral proteins produced in the lab, not live organisms. Polio and meningococcal vaccines are typically inactivated or subunit vaccines, meaning they do not contain replicating organisms. Influenza vaccines are normally inactivated vaccines, though a live attenuated nasal spray exists in some settings, it is not the standard form used in most contexts.

Live vaccines use weakened forms of viruses or bacteria that can still replicate in the body, triggering a strong and lasting immune response without causing disease in healthy people. The two vaccines that fit this pattern are measles-mumps-rubella (MMR) and varicella (chickenpox). They contain attenuated (weakened) viruses that replicate just enough to train the immune system.

Other options don’t fit the live-vaccine category. HPV vaccines are recombinant subunit vaccines—they use viral proteins produced in the lab, not live organisms. Polio and meningococcal vaccines are typically inactivated or subunit vaccines, meaning they do not contain replicating organisms. Influenza vaccines are normally inactivated vaccines, though a live attenuated nasal spray exists in some settings, it is not the standard form used in most contexts.